我试图旋转一个UIImageView 360度，并在网上看了几个教程。我不能让它们都工作，UIView要么停止，要么跳转到一个新位置。
我怎样才能做到这一点呢?
我最近尝试的是:
[UIView animateWithDuration:1.0
delay:0.0
options:0
animations:^{
imageToMove.transform = CGAffineTransformMakeRotation(M_PI);
}
completion:^(BOOL finished){
NSLog(@"Done!");
}];
但如果我使用2*pi，它根本不会移动(因为它是相同的位置)。如果我尝试只做(180度)，它可以工作，但如果我再次调用这个方法，它会向后旋转。
编辑:
[UIView animateWithDuration:1.0
delay:0.0
options:0
animations:^{
[UIView setAnimationRepeatCount:HUGE_VALF];
[UIView setAnimationBeginsFromCurrentState:YES];
imageToMove.transform = CGAffineTransformMakeRotation(M_PI);
}
completion:^(BOOL finished){
NSLog(@"Done!");
}];
也不管用。它会转到180度，暂停一秒钟，然后在重新开始之前重置回0度。
我在这个库中找到了很好的代码，
下面是它的代码，我做了一些小的改变，根据我的速度需要:)
UIImageView + Rotate.h
#import <Foundation/Foundation.h>
@interface UIImageView (Rotate)
- (void)rotate360WithDuration:(CGFloat)duration repeatCount:(float)repeatCount;
- (void)pauseAnimations;
- (void)resumeAnimations;
- (void)stopAllAnimations;
@end
UIImageView + Rotate.m
#import <QuartzCore/QuartzCore.h>
#import "UIImageView+Rotate.h"
@implementation UIImageView (Rotate)
- (void)rotate360WithDuration:(CGFloat)duration repeatCount:(float)repeatCount
{
CABasicAnimation *fullRotation;
fullRotation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
fullRotation.fromValue = [NSNumber numberWithFloat:0];
//fullRotation.toValue = [NSNumber numberWithFloat:(2*M_PI)];
fullRotation.toValue = [NSNumber numberWithFloat:-(2*M_PI)]; // added this minus sign as i want to rotate it to anticlockwise
fullRotation.duration = duration;
fullRotation.speed = 2.0f; // Changed rotation speed
if (repeatCount == 0)
fullRotation.repeatCount = MAXFLOAT;
else
fullRotation.repeatCount = repeatCount;
[self.layer addAnimation:fullRotation forKey:@"360"];
}
//Not using this methods :)
- (void)stopAllAnimations
{
[self.layer removeAllAnimations];
};
- (void)pauseAnimations
{
[self pauseLayer:self.layer];
}
- (void)resumeAnimations
{
[self resumeLayer:self.layer];
}
- (void)pauseLayer:(CALayer *)layer
{
CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
layer.speed = 0.0;
layer.timeOffset = pausedTime;
}
- (void)resumeLayer:(CALayer *)layer
{
CFTimeInterval pausedTime = [layer timeOffset];
layer.speed = 1.0;
layer.timeOffset = 0.0;
layer.beginTime = 0.0;
CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
layer.beginTime = timeSincePause;
}
@end
在Swift中，你可以使用以下代码进行无限旋转:
斯威夫特4
extension UIView {
private static let kRotationAnimationKey = "rotationanimationkey"
func rotate(duration: Double = 1) {
if layer.animation(forKey: UIView.kRotationAnimationKey) == nil {
let rotationAnimation = CABasicAnimation(keyPath: "transform.rotation")
rotationAnimation.fromValue = 0.0
rotationAnimation.toValue = Float.pi * 2.0
rotationAnimation.duration = duration
rotationAnimation.repeatCount = Float.infinity
layer.add(rotationAnimation, forKey: UIView.kRotationAnimationKey)
}
}
func stopRotating() {
if layer.animation(forKey: UIView.kRotationAnimationKey) != nil {
layer.removeAnimation(forKey: UIView.kRotationAnimationKey)
}
}
}
斯威夫特3
let kRotationAnimationKey = "com.myapplication.rotationanimationkey" // Any key
func rotateView(view: UIView, duration: Double = 1) {
if view.layer.animationForKey(kRotationAnimationKey) == nil {
let rotationAnimation = CABasicAnimation(keyPath: "transform.rotation")
rotationAnimation.fromValue = 0.0
rotationAnimation.toValue = Float(M_PI * 2.0)
rotationAnimation.duration = duration
rotationAnimation.repeatCount = Float.infinity
view.layer.addAnimation(rotationAnimation, forKey: kRotationAnimationKey)
}
}
停下来就像:
func stopRotatingView(view: UIView) {
if view.layer.animationForKey(kRotationAnimationKey) != nil {
view.layer.removeAnimationForKey(kRotationAnimationKey)
}
}
@ram的回答很有帮助。以下是Swift版本的答案。
斯威夫特2
private func rotateImageView() {
UIView.animateWithDuration(1, delay: 0, options: UIViewAnimationOptions.CurveLinear, animations: { () -> Void in
self.imageView.transform = CGAffineTransformRotate(self.imageView.transform, CGFloat(M_PI_2))
}) { (finished) -> Void in
if finished {
self.rotateImageView()
}
}
}
斯威夫特3、4、5所示
private func rotateImageView() {
UIView.animate(withDuration: 1, delay: 0, options: UIView.AnimationOptions.curveLinear, animations: { () -> Void in
self.imageView.transform = self.imageView.transform.rotated(by: .pi / 2)
}) { (finished) -> Void in
if finished {
self.rotateImageView()
}
}
}
这是我的快速解决方案作为一个UIView扩展。它可以被认为是任何UIImageView上UIActivityIndicator行为的模拟。
import UIKit
extension UIView
{
/**
Starts rotating the view around Z axis.
@param duration Duration of one full 360 degrees rotation. One second is default.
@param repeatCount How many times the spin should be done. If not provided, the view will spin forever.
@param clockwise Direction of the rotation. Default is clockwise (true).
*/
func startZRotation(duration duration: CFTimeInterval = 1, repeatCount: Float = Float.infinity, clockwise: Bool = true)
{
if self.layer.animationForKey("transform.rotation.z") != nil {
return
}
let animation = CABasicAnimation(keyPath: "transform.rotation.z")
let direction = clockwise ? 1.0 : -1.0
animation.toValue = NSNumber(double: M_PI * 2 * direction)
animation.duration = duration
animation.cumulative = true
animation.repeatCount = repeatCount
self.layer.addAnimation(animation, forKey:"transform.rotation.z")
}
/// Stop rotating the view around Z axis.
func stopZRotation()
{
self.layer.removeAnimationForKey("transform.rotation.z")
}
}
